<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body th:inline="text">
kong.html
    <h1 th:text="${user}">空</h1>
<!--原本就是空-->
<h1 th:if="${user.id eq null}">is null</h1>
       userid: <h2 th:text="${user.id}">id空</h2>
   >>>>> username:<span th:text="${user.username}">username空</span>
   >>>>>userage: <span th:text="${user.age}">age空</span>


</body>
</html>